Adjustable double balloon catheter with a through lumen for stone management

ABSTRACT

A method for removing an object from a body lumen includes dispensing fluid into the body lumen, and causing the dispensed fluid to propel the object along the body lumen. A device for removing an object from a body lumen includes a fluid dispenser for dispensing fluid into the body lumen, and a pump in fluid communication with the dispenser.

TECHNICAL FIELD

[0001] The invention relates to minimally invasive medical devices and procedures, and, more particularly, to devices and procedures for removing kidney stones.

BACKGROUND INFORMATION

[0002] Various methods exist to remove calculi from body cavities. Calculi, such as those formed in a gall bladder or kidney, can cause significant problems for a patient. For example, ureteral constriction and blockage can cause hydronepherosis, a condition characterized by the damming of urine in the kidneys. A frequent blockage site is the junction of the ureter and the renal pelvis. Acquired blockages are most commonly caused by kidney stones that root themselves in the ureteral lumen wall.

[0003] Often, kidney stone removal is performed using stone retrieval devices based on wire baskets, lithotrypsies, pharmaceutical therapeutics or surgery. For example, a cystoscope can be introduced into the ureter to remove an embedded stone. The cytoscope typically includes a wire basket disposed at the distal end. The stone is trapped in the basket, and the cystoscope and trapped stone are then removed from the body.

[0004] Existing methods have several deficiencies. These treatments can be difficult to perform, can lead to severe adverse events, and can entail high cost. For example, a retrieval basket can have difficulty trapping calculi of some sizes or shapes. Body tissues can be damaged while spreading the basket and attempting to grasp a stone. A basket may have difficulty grasping a stone that is embedded in a wall of a body lumen. Further, the size of the basket/stone combination may create difficulty in removing the apparatus from the body. Use of ultrasound or solvents can damage body tissues in the vicinity of the stone.

SUMMARY OF THE INVENTION

[0005] Methods and devices of the invention enable removal of objects from body lumens with relatively low cost and low incidence of adverse effects. Generally, methods and devices according to invention involve the use of a fluid dispensed into a body lumen to dislodge and/or propel an object in the body lumen. The body lumen can be distended to assist the release of an embedded object.

[0006] For example, a kidney stone can be propelled from a ureter into a bladder, without recourse to chemicals, drugs, wire baskets, lithotrypsy or surgery. The invention thus provides an out-patient procedure, that can be performed under a local anesthetic. Some procedures of the invention provide a less painful treatment than many conventional procedures.

[0007] Accordingly, in one aspect, the invention features a method for removing an object from a body lumen. The method includes dispensing fluid into the body lumen, and causing the dispensed fluid to propel the object along the body lumen. For example, the object can be a kidney stone lodged in a ureter, and the dispensed fluid propels the stone along the ureter, towards the bladder.

[0008] The method can include positioning a fluid dispenser in the body lumen to dispense the fluid. The flow of the dispensed fluid can be impeded in at least one direction through the body lumen. For example, when a kidney stone is being removed from a ureter, the flow of the dispensed fluid can be impeded through the ureter towards the kidney.

[0009] In one embodiment, a predetermined quantity of the dispensed fluid is confined within a portion of the body lumen. The portion of the body lumen contains the object. The fluid can be confined by impeding the flow of the fluid at a distal end and at a proximal end of the portion of the body lumen, for example, with clamps or expanded balloons. The predetermined quantity of fluid can be released through the proximal end of the portion of the body lumen to propel the object past the proximal end of the portion of the body lumen.

[0010] In some embodiments, the distance between the proximal end and the distal end of the portion of the body lumen is decreased to cause an increase in a fluid turbulence within the body lumen when the fluid is released. Dispensing and releasing predetermined quantities of fluid can be repeated to dislodge and/or propel the object in lumen.

[0011] The portion of the body lumen can be allowed to expand while confining the dispensed fluid, to ease the movement of the object through the body lumen.

[0012] The fluid can be dispensed at a predetermined pressure level, or dispensed until a predetermined pressure level is attained. The pressure of the dispensed fluid can be varied to dislodge the object from a wall of the body lumen.

[0013] The method can further include positioning a distal balloon within the body lumen at a distal end of a portion of the body lumen that contains the object, and positioning a proximal balloon within the body lumen at the proximal end of the portion of the body lumen. The dispensed fluid can then propel the object by pressurizing the proximal balloon to a lower pressure than a pressure of the distal balloon to permit a flow of the fluid past the proximal balloon.

[0014] In another embodiment, the pressure of the proximal balloon is decreased after the predetermined quantity of fluid is dispensed. The quantity of fluid can then flow past the proximal end of the portion of the body lumen, to remove the object.

[0015] In general, in another aspect, the invention features a device for removing an object from a body lumen. The device includes a fluid dispenser for dispensing a fluid into the body lumen, and a pump in fluid communication with the fluid dispenser, the pump comprising a fluid volume controller configured to provide a sufficient quantity of fluid to cause the object to move through the body lumen. The device includes a distal expansible member, for example, a balloon, in mechanical communication with the fluid dispenser to stabilize the location of the fluid dispenser within the body lumen when the distal expansible member is in an expanded state.

[0016] The fluid dispenser defines an aperture through which the fluid is dispensed into the body lumen. Also, a proximal expansible member can be in mechanical communication with the fluid dispenser, with the aperture disposed between the distal and proximal expansible members. Expansion and contraction of the proximal expansible member can then control a flow of the fluid past the proximal expansible member.

[0017] The distal expansible member can include a balloon that is inflated to a greater pressure than the pressure of the proximal expansible member, to permit the fluid to flow past the proximal expansible member.

[0018] The device can include a pump to pump the fluid to the fluid dispenser. The pump can include a non-positive displacement pump having a preset pressure limit, or a positive displacement pump having a relief valve with a preset pressure limit. The pump can be built into a handle. The pump can also include a pressure controller configured to provide a sufficient pressure to displace the object in the body lumen.

[0019] The foregoing and other objects, aspects, features, and advantages of the invention will become more apparent from the following description and from the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In the drawings, like reference characters generally refer to the same parts throughout the different views. Also, the drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention.

[0021]FIG. 1 is a cross-sectional view of a body lumen containing a blockage, which illustrates a method of removing an object from the body lumen, according to general principles of the invention.

[0022]FIG. 2 is a cross-sectional view of an embodiment of a device for removing an object from a body lumen, with the device positioned in a body lumen that has an embedded object.

[0023]FIG. 3 is a cross-sectional view of an embodiment of a device that includes a fluid dispenser, which includes a catheter.

[0024] FIGS. 4A-4E are cross-sectional views of the device of FIG. 3 in a body lumen, which illustrate steps in some embodiments of methods for removing an object from the body lumen.

[0025]FIG. 5 is a cross-sectional view of an embodiment of a device that is positioned within a ureter for removal of a kidney stone.

DESCRIPTION

[0026] Now referring to FIG. 1, general principles of an exemplary embodiment of the invention are described. FIG. 1 is a cross-sectional view of a body lumen containing a blockage. The lumen is defined by a duct 15, for example, a ureter. An object 10, for example, a kidney stone, partially blocks the duct 15. According to a general principle of the invention, a fluid 11 introduced into the duct 15 serves to dislodge the object 10 from the lumen wall of the duct 15 and/or propel the object 10 through the lumen.

[0027] If the object 10 is embedded in the wall of the duct 15, it can be dislodged by the flow of the fluid. The fluid can also distend the duct, to help dislodge the object 10, and/or to help move the object 10 through the lumen by increasing the width of the lumen.

[0028] Now referring to FIG. 2, an embodiment of a device for removing an object from a body lumen is described. FIG. 2 is a cross-sectional view of the device 20 positioned in a body lumen. An object 10 is embedded in the wall of the body lumen. The device 20 includes a catheter 22, a fluid lumen 23 defined by the catheter 22, an aperture 23A that is in fluid communication with the fluid lumen 23, and a member 21 located at a distal end of the catheter 22.

[0029] To remove the object 10 from the body lumen, a portion of the catheter 22 is placed within the body lumen, with the member 21 to one side of the object 10. The member 21 then serves to hold the device in position by pressing against the walls of the body lumen. The member 21 may be expansible, and can include, for example, a balloon or a gel. A fluid 11, for example, a saline solution, is directed through the fluid lumen 23. The fluid 11 exits the lumen 23 via the aperture 23A. Movement of the fluid 11 within the body lumen can dislodge the object 10, and can propel the object 10 through the body lumen. The member 21 can block the flow of fluid 11 in a direction that is away from the object 10.

[0030] The device 20 can be configured to deliver fluid of a sufficient quantity or pressure to dislodge or propel the object. Further, the quantity of fluid and the pressure of the fluid can be restricted to levels that are unlikely to cause any undesirable side effects for a patient.

[0031] Now referring to FIG. 3, a preferred embodiment of a device for removing an object from a body lumen is described. FIG. 3 is a cross-sectional view of a device 30. The device 30 includes a fluid dispenser, which includes a first catheter 32, and a second catheter 36. A portion of the first catheter 32 is disposed within the second catheter 36, and can slide with respect to the second catheter 36.

[0032] The first catheter includes a fluid lumen 33, through which fluid 11 can be delivered to a body lumen. A distal expansible member 31, is in mechanical communication with the first catheter 32, and a proximal expansible member 38 is in mechanical communication with the second catheter 36.

[0033] In a preferred embodiment, the expansible members 31, 38 are balloons. The catheters 32, 36 include lumens 34, 37 for delivery of inflation fluid to the balloons. A fluid, such as a saline solution, can be added or removed from a balloon 31, 38 to control the size of the balloon 31, 38, and to control the pressure of the balloon 31, 38 against the wall of the body lumen.

[0034] Now referring to FIGS. 4A-4E, some illustrative embodiments are described of methods for removing an object from a body lumen, which utilize the device 30 of FIG. 3. FIGS. 4A-4E are cross-sectional views of the device 30 in a body lumen, which illustrate steps in some embodiments of methods for removing an object for the body lumen.

[0035] A portion of the device 30 is inserted into the body lumen, while the balloons 31, 38 are in a collapsed state (see FIG. 4A). The spacing between the balloons 31, 38 can be adjusted by sliding the catheters 32, 36 relative to each other (see double arrow in FIG. 4A.) The distal balloon can then be expanded to secure the position of the first catheter 32 within the body lumen (see FIG. 4B).

[0036] The proximal balloon 38 can be expanded before, simultaneously with, or after the expansion of the distal balloon 31. In one embodiment, the proximal balloon is inflated to a lower pressure, P₂, than the pressure, P₁, of the distal balloon. Fluid 11 is then dispensed into the >portion of the body lumen defined by the balloons 31, 38. When the pressure of the fluid 11 exceeds that of the pressure of the proximal balloon 38, the fluid 11 begins to flow past the proximal balloon 38. The flow of the fluid 11 against the object 10 can dislodge the object and can propel the object through the lumen, past the proximal balloon 38 (see FIG. 4C.)

[0037] In some embodiments, the pressure of the proximal balloon 38 is decreased to enhance the flow of fluid 11, after depositing a predetermined quantity of fluid 11 into the portion of the body lumen, or depositing fluid 11 to a predetermined pressure.

[0038] In some embodiments, a predetermined quantity fluid is dispensed while the balloons are fully inflated (see FIG. 4D.) The predetermined quantity of fluid causes the portion of the body lumen to become distended. This stretching of the body lumen can help dislodge the object 10 from the wall of the body lumen. The proximal balloon 38 can then be reduced in size, for example, fully collapsed, to permit the dispensed fluid 11 to flow past the proximal balloon 38 (see FIG. 4E.) The distal balloon 31 remains expanded, in part, to block fluid 11 from flowing in a distal direction past the location of the distal balloon 31.

[0039] Dispensing a predetermined quantity of fluid, and releasing the predetermined quantity of fluid, can be repeated until the object is dislodged and/or flushed past the proximal balloon 38. In some embodiments, the fluid 11 is dispensed at a sufficient pressure while the fluid 11 flows against the object 10 to dislodge the object 10 and/or to cause the object to move through the body lumen.

[0040] A device can further include aids to help the positioning of the device in the body lumen. For example, a balloon can include radio-opaque markers that provide visibility under fluoroscopic imaging devices.

[0041] A device can include balloons that are, for example, selected from those known in the catheter arts. A balloon can include various materials, for example, urethane, silicone or other elastomer. The balloons can have separate inflation supplies, to permit different balloon pressures. The fluid delivered to the body lumen can be a saline solution or other biocompatible materials, for example, other isotonic fluids, for example, a fluorocarbon.

[0042] Now referring to FIG. 5, embodiments of a device and method of removal of a kidney stone from a ureter are described. FIG. 5 is a cross-sectional view of a device that is positioned within a ureter 55, which leads to a kidney 56, for removal of a kidney stone 50.

[0043] The device is similar in construction to the device of FIG. 3. The device includes a catheter 37, which has been inserted through the urethra and bladder 57 into the ureter 55. The ureter 55 is obstructed by the kidney stone 50. A proximal balloon 38A, attached to a second catheter 36A, and a distal balloon 31A, attached to a first catheter 32A, have been positioned on either side of the stone 50.

[0044] The catheter 37 extends to a pump 53, which directs saline fluid 11A under pressure to the portion of the ureter 55 that contains the stone 50. The pump 53 is powered by a motor 54, and is held within a handle 52. The device also includes a fluid source 51, which supplies saline fluid 11A to the pump 53. In some embodiments, the pump 53, the motor 54, the handle 52 and/or the fluid source 51 remain outside the body.

[0045] In preferred embodiments, the pump 53 includes features that prevent application of a damaging pressure to body tissue. In one embodiment, the pump is a non-positive displacement pump having a preset pressure limit. In another embodiment, the pump is a positive displacement pump having a pressure release, limiting valve.

[0046] A preferred embodiment of a method of using the device of FIG. 5 includes advancing the catheter 32A through the urinary tract, under fluoroscopic guidance, to the site of an ingrown stone. The distal balloon 31A is inflated with saline solution once the balloon 31A is at the desired location. The proximal balloon 38A is then advanced with the second catheter 36A, by sliding the second catheter 36A relative to the first catheter 32A, until the distance between the proximal and distal balloons 31A, 38A is at a preferred separation. For example, upon release of a quantity of saline fluid 11A, it is possible to obtain greater fluid velocity and turbulence through use of reduced separation between the balloons 31A, 38A.

[0047] A guidewire can be utilized to assist insertion of the device. A variety of suitable guidewires are known to those having experience in the catheter arts.

[0048] The proximal balloon 38A is then inflated with saline solution until it exerts a pressure, on the ureter wall, that is less than the pressure exerted by the distal balloon 31A. A tight seal at the distal balloon 31A, and a loose seal at the proximal balloon 38A are obtained. Warm, high-pressure saline is then flushed through the ureter, and the excess flows past the proximal balloon 38A, and into the bladder 57.

[0049] The fluid 11A dislodges the stone, and flushes it into the bladder 57. The balloons 31A, 38A are then deflated, and the device is removed from the body. The stone 50 can be removed from the bladder 57 by, for example, conventional means.

[0050] A variable spacing between balloons has further advantages. For example, the spacing can be varied to include more than one stone in a body lumen portion, when needed. The spacing can be varied to provide variable saline flush pressures.

[0051] Variations, modifications, and other implementations of what is described herein will occur to those of ordinary skill in the art without departing from the spirit and the scope of the invention as claimed. For example: an embodiment of a device can include fixed balloons to provide a more stable configuration and simpler manufacturing; a catheter can include a printed electroactive polymer to provide self-propulsion; balloons can be coated, for example, with hydrogels, drugs or polymers; and a drug can be delivered to the vicinity of an object via the fluid lumen. Accordingly, the invention is to be defined not by the preceding illustrative description but instead by the spirit and scope of the following claims. 

What is claimed is:
 1. A method for removing an object from a body lumen, comprising: dispensing fluid into the body lumen; confining a predetermined quantity of the dispensed fluid within a portion of the body lumen that contains the object by impeding a flow of the fluid at a distal end and at a proximal end of the portion of the body lumen; and releasing the predetermined quantity of fluid through the proximal end of the portion of the body lumen to propel the object past the proximal end of the portion of the body lumen.
 2. A method for removing an object from a body lumen, comprising: dispensing fluid into the body lumen; and causing the dispensed fluid to propel the object along the body lumen.
 3. The method of claim 2, further comprising positioning a fluid dispenser in the body lumen, and wherein dispensing comprises dispensing the fluid from the fluid dispenser.
 4. The method of claim 2, further comprising impeding a flow of the dispensed fluid in at least one direction through the body lumen.
 5. The method of claim 4, wherein impeding comprises impeding the flow of the dispensed fluid through a ureter towards a kidney.
 6. The method of claim 2, further comprising confining a predetermined quantity of dispensed fluid within a portion of the body lumen that contains the object; and wherein causing the dispensed fluid to propel comprises releasing the fluid from the portion of the body lumen.
 7. The method of claim 6, wherein confining comprises impeding a flow of the fluid at a distal end and at a proximal end of the portion of the body lumen, and wherein causing the dispensed fluid to propel comprises releasing the flow of the fluid through the proximal end of the portion of the body lumen, to propel the object past the proximal end of the portion of the body lumen.
 8. The method of claim 7, further comprising reducing a distance between the proximal end and the distal end of the portion of the body lumen to cause an increase in a fluid turbulence within the body lumen when the fluid is released.
 9. The method of claim 7, wherein dispensing and causing the dispensed fluid to propel are repeated to dislodge the object from a wall of the body lumen.
 10. The method of claim 7, wherein impeding comprises causing the portion of the body lumen to expand to ease a movement of the object.
 11. The method of claim 2, wherein dispensing comprises dispensing the fluid into a ureter, and causing the dispensed fluid to propel comprises causing the dispensed fluid to propel a kidney stone along the ureter into a bladder.
 12. The method of claim 2, wherein causing the dispensed fluid to propel comprises dispensing fluid until a predetermined pressure level of the fluid is reached.
 13. The method of claim 2, wherein dispensing comprises causing a pressure of the dispensed fluid to vary to dislodge the object from a wall of the body lumen.
 14. The method of claim 2, further comprising: positioning a distal balloon within the body lumen at a distal end of a portion of the body lumen that contains the object; and positioning a proximal balloon within the body lumen at the proximal end of the portion of the body lumen, and wherein causing the dispensed fluid to propel comprises pressurizing the proximal balloon to a lower pressure than a pressure of the distal balloon to permit a flow of the fluid past the proximal balloon.
 15. A device for removing an object from a body lumen, comprising: a fluid dispenser for dispensing a fluid into the body lumen; and a pump in fluid communication with the fluid dispenser, the pump comprising a fluid volume controller configured to provide a sufficient quantity of fluid to cause the object to move through the body lumen.
 16. The device of claim 15 further comprising a distal expansible member in mechanical communication with the fluid dispenser to stabilize the location of the fluid dispenser within the body lumen when the distal expansible member is in an expanded state.
 17. The device of claim 16, wherein the fluid dispenser defines an aperture through which the fluid is dispensed into the body lumen, and further comprising a proximal expansible member in mechanical communication with the fluid dispenser, the aperture disposed between the distal and proximal expansible members, wherein an expansion and a contraction of the proximal expansible member controls a flow of the fluid past the proximal expansible member.
 18. The device of claim 17 wherein the proximal expansible member and the distal expansible member have a fixed spatial separation.
 19. The device of claim 17 wherein the proximal expansible member is in slidable communication with the fluid dispenser.
 20. The device of claim 17, wherein the proximal expansible member comprises a balloon, and the distal expansible member comprises a balloon that has a greater pressure than an a pressure of the proximal expansible member to permit the fluid to flow past the proximal expansible member.
 21. The device of claim 15, wherein the distal expansible member comprises a balloon.
 22. The device of claim 15, wherein the distal expansible member comprises a gel.
 23. The device of claim 15 wherein the fluid dispenser comprises a first catheter defining a fluid lumen for conveying the fluid from the pump to the body lumen.
 24. The device of claim 23 further comprising a second catheter in slidable communication with the first catheter, and in fixed physical communication with a proximal expansible member, to permit a variation in a spacing between the distal and proximal expansible members by sliding the first and second catheters relative to each other.
 25. The device of claim 16, wherein the fluid dispenser is configured to dispense the fluid into the body lumen on a proximate side of the distal expansible member, and the distal expansible member is expanded to impede a flow of the fluid in a distal direction through the body lumen.
 26. The device of claim 15, wherein the fluid dispenser comprises an electroactive material to assist positioning of the fluid dispenser within the body lumen.
 27. The device of claim 15, wherein the fluid is a saline solution.
 28. The device of claim 15, wherein the pump comprises a non-positive displacement pump having a preset pressure limit.
 29. The device of claim 15, wherein the pump comprises a positive displacement pump comprising a relief valve having a preset pressure limit.
 30. The device of claim 15, further comprising a handle that mechanically supports the pump.
 31. The device of claim 15, wherein the pump further comprises a pressure controller that is configured to provide a sufficient pressure to displace the object in the body lumen. 